Grinding apparatus

ABSTRACT

THIS INVENTION IS A GRINDING APPARATUS WHEREIN ON A REVOLVING DRUM IS MOUNTED A CONTAINER ECCENTRICALLY AT BOTH ENDS ON EACH PARALLEL WITH THE SHAFT OF SAID DRUM SO THAT A FLOW IN THE FORM OF THE FIGURE 8 MAY BE GIVE TO ABRASIVE AND OBJECTS TO BE GROUND CONTAINED IN SAID CONTAINER.

vFeb- 16, 7 IETATSU OHNO 3,562,962

GRINDING APPARATUS Filed Feb. 26, 1969 V 2 SheetsSheet 1 Feb. 16, 1971 'IETATSU OHNO 3,562,962

GRINDING APPARATUS Filed Feb. 26,. 1969 2 SheetsSheet z United States Patent GRINDING APPARATUS Ietatsu Ohno, 14-2-406 Mure, Mitaka, Tokyo, Japan Filed Feb. 26, 1969, Ser. No. 802,369 Int. Cl. B24b 31/02; B01f 9/00 US. Cl. 51-163 2 Claims ABSTRACT OF THE DISCLOSURE This invention is a grinding apparatus wherein on a revolving drum is mounted a container eccentrically at both ends on each shaft parallel with the shaft of said drum so that a flow in the form of the figure 8 may be given to abrasives and objects to be ground contained in said container.

This invention relates to grinding apparatus.

In the case of grinding such comparatively small articles of complicated forms as, for example, watch parts, hosiery needles and injection needles, when the objects to be ground and a proper abrasive are contained in a sealed container, the container is fitted to the peripheral edge part of a drum and said drum is rotated at a high speed, while the object to be ground and the abrasives are strongly pressed against each other by a centrifugal force, fine vibrations will be produced and therefore a grinding action will take place. In such apparatus, if a rotating motion is given to the above mentioned container, while the abrasives and others always tend to be positioned in the outer peripheral part of the drum by the centrifugal force, as the container rotates, the abrasives will relatively flow in the container. Therefore, the friction between the objects to be ground and the abrasives will increase and the grinding efficiency will improve. According to the present invention, in the above mentioned apparatus, each container is fitted as inclined to the outer peripheral part of the drum so that the grinding efficiency may further improve and at the same time even parts of complicated forms may be ground uniformly on the entire surface.

Therefore, an object of the present invention is to provide a grinding apparatus wherein the motion of the abrasives and objects to be ground is complicated so that the grinding efiiciency may remarkably increase.

In the accompanying drawings:

'FIG. 1 is a side view of a grinding apparatus according to the present invention;

FIG. 2 is a vertical sectional view on line II-Il in FIG. 1;

FIG. 3 is an elevation of FIG. 1;

FIG. 4 is a vertical sectional view on line IV--IV in FIG. 1;

FIGS. 5a to 5d are sectional views respectively on lines C-C, -D-D, EE and F- F in FIG. 4;

FIG. 6 is a view showing the directions of the motion of the abrasives in the container;

FIG. 7 is a vertical sectional view of FIG. 6.

In explaining the present invention with reference to the accompanying drawings, in FIGS. 1 to 3 showing an embodiment of the present invention, a shaft 2 is fixed to a base 1 and a rotary drum 3 is loosely fitted to said shaft 2. Said drum 3 is made by connecting and fixing two disks 4 and 5 through a shaft 6', a pulley 7 is fixed to one disk 4 and a belt is engaged on said pulley 7 and a pulley 9 of a motor 8 provided on the base 1. Four rotary shafts 11 are rotatably fitted to the peripheral edge parts of said two disks 4 and 5. The drum 3 is rotated at a speed, for example, of 200 rpm. through the belt 10 by the rotation of the motor 8.

The rotary shafts 11 are parallel with the shaft 2 and are arranged symmetrically with respect to the shaft ice 2 but a cylindrical or polygonal container 12 having an opening in the top part is fitted to the middle part of each shaft 11 so that its rotating axis may be inclined. A lid 13 is provided on the opening in the top part of the container 12 so as to be removably fixed to the container 12 by any proper means. Four gears 14 fixed to the respective shafts 11 and four gears 15 journaled on said disk 5 are provided on the outside of the other disk 5 of the drum 3 and the gears :14 are respectively meshed with the gears 15. A shaft 24 is journaled on the shaft 2. A gear 16 is fixed to said shaft 24 and is meshed with the gears 15. Said shaft 24 is surrounded with a forked piece L17 which is supported in the top part with the base 1 through a pin 18. The oppositely threaded part 20 of a rod 19 is screwed through the forked piece '17 near the forward ends so that when a handle 21 provided at the other end of said rod 19 is rotated, the clearance of the forked piece 17 may be increased or decreased and, when said clearance is decreased, the shaft 24 may be held and fixed but, on the contrary, when said clearance is increased, the shaft 24 may freely rotate.

The lid 13 is removed, abrasives 22, objects 23 and a proper amount of water are contained in the container 12 and then the lid 13 is again applied. In such case, when the shaft 24 is freed from the forked piece .17, as the container 12 can rotate freely independently of the rotation of the drum 3, the abrasives and objects to be ground can be put into each container 12 after directing the container in any proper direction and removing the lid 13. Then, when the shaft 24 is held and fixed with the forked piece .17 and the drum 3 is rotated in the direction indicated by the arrow p in FIG. 2, the gears 14 and 15 will rotate respectively in the directions indicated by the arrows r and q. If the diameters of the gears 16, 15 and 14 are the same, with one rotation of the drum 3, the gear 14 Will also ma'ke one rotation in the direction indicated by the arrows r. That is to say, as shown in FIG. 4, when the drum 3 rotates in the direction indicated by the arrow p and the container 12 revolves around the shaft 2, said container 12 will rotate at the same angular velocity in the direction indicated by the arrow r. Further, the abrasives 22 and objects 23 to be ground Within the cylindrical or polygonal container 12 always tend to be positioned in the outer peripheral direction of the container due to the centrifugal force by the above mentioned revolution. Therefore, within the container 12, the abrasives 22 flows in the direction indiform of the figure 8 is given to abrasives and objects As the container 12 rotates in the direction indicated by the arrow r as synchronized with the rotation of the drum 3, it will be in such states as are shown in FIG. 5. By the way, FIG. 5 shows the sections of the respective containers. However, it is needless to say that, in case one container 12 has moved to the respective positions shown in FIG. 5, it will be also in the same states. That is to say, in the respective states in FIGS. 5a, 5b, 5c and 5d, the abrasives 22 and objects 23 to be ground always tend to be positioned outward of the drum 3 due to the centrifugal force as shown in FIG. 5. Therefore, the abrasives and objects to be ground reciprocate axially in the direc tions indicated by the arrows t, u, v and w within the container 12.

Thus, in the apparatus of the present invention, as each cylindrical or polygonal container is fitted as inclined to the rotary shaft 11 and the shaft 2, not only a rotary flow in such peripheral direction as is indicated by the arrow s but also a reciprocating flow in such lateral directions as are indicated by the arrows t, u, v and w takes place. Therefore, it is as shown in FIGS. 6 and 7 that a rotary centrifugal flow and a flow in the form of the figure 8 in the vertical, horizontal and diagonal directions are made. Thus the abrasives and the objects to be ground 'fiow over all to be agitated.

As in the above mentioned embodiment, in the apparatus of the present invention, as each container 12 is fitted as inclined, a reciprocating motion in the axial direction can be caused to the abrasives and objects to be ground by the action of the centrifugal force. Therefore, the abrasives 22 and the objects 23 to be ground make a very complicated motion together with a rotary flow by the rotation of the container so as to be perfectly agitated. That is to say, the motion of the abrasives and objects to be ground in the container is severe and is not simple, therefore the grinding efficiency increases and objects to be ground of any complicated form can be ground uniformly in each part. Further, when bodies, for example, in the form of thin plates were ground with a conventional apparatus in which the motion was simple, the two bodies to be ground moved as pasted together with water and were not ground at all on the pasted surfaces in some case. On the other hand, according to the apparatus of the present invention, the motion is so complicated that such two objects to be ground will easily separate from each other and will be ground uniformly on the entire surfaces. The above described embodiment is of the case that the angular velocity of the rotation and the angular velocity of the revolution are the same. However, it is needless to say that they can be made different, for example, by selecting the diameters of the gears 12, 10 and 9. It is also possible to contain a plurality of containers in one container.

What I claim is:

1. A grinding apparatus comprising a rotary drum connected to a driving source and fitted on a shaft journaled on a base, a cylindrical or polygonal container provided on each of a plurality of rotary shafts parallel with the shaft of said drum, said container being fitted as inclined to said rotary shaft and means for giving a revolving motion to said rotary drum and at the same time giving a rotating motion to the container, whereby a flow in the form of the figure 8 is given to abrasives and objects to be ground contained in the container by the rotation of the rotary drum and the container.

2. A grinding apparatus according to claim 1 wherein a gear (14) on the shaft of each container, a gear (15) journaled on the disk of the drum and a gear (24) on a shaft provided coaxially with the shaft (2) of the rotary drum are meshed with one another and said gear (24) is to be able to be fixed or rotated by a clutch mechanism.

References Cited UNITED STATES PATENTS 3,078,623 2/1963 Stanley 51-164 FOREIGN PATENTS 685,711 1/1953 Great Britain.

HAROLD D. WHITEHEA'D, Primary Examiner US. Cl. X.R. 259--57 

